Severe cytopenia after chimeric antigen receptor-T cell driven by large granular lymphocytes and responsive to steroids.

Immune effector cell-associated hematotoxicity (ICAHT) is a common toxicity associated with an important morbidity after chimeric antigen receptor (CAR)-T-cell therapy. Multiple factors seem to be involved in the development of severe ICAHT, making its management difficult. Here, we report three cases of severe ICAHT after axicabtagene-ciloleucel (axi-cel) for diffuse large B-cell lymphoma showing an expansion of large granular lymphocyte in the bone marrow with a CD3/CD57-positive non-CAR-T immunophenotype. We show that it is possible to treat them with low-dose steroids, obtaining a striking resolution of cytopenias with no deleterious impact on the underlying malignancy.